Make test reports deterministic in the face of nondeterminism #715
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The concurrency tests for multi-threaded collections run for a nondeterministic number of iterations. This means that each time you run them, the numbers in the message ``` All tests passed (314159 assertions in 2718 test cases) ``` are different. This does not contribute to confidence that the tests are working. There is also a problem with the REQUIRE macro: It does not support concurrent usage from multiple threads. If two threads perform a REQUIRE at the same time, the assertion count is unreliable. Fix both problems by not using REQUIRE (1) in nondeterministic ways or (2) from multiple threads simultaneously. Instead, we use `check_bool`, which will still throw an exception and fail the test, but does not run afoul of REQUIRE's limitations.
kennykerr
approved these changes
Aug 1, 2020
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The concurrency tests for multi-threaded collections run for a nondeterministic number of iterations, and the branches taken within the test are nondeterministic, causing the REQUIRE macro to be called a nondeterministic number of times during the run of the test. This means that each time you run the tests, the numbers in the message
are different. This does not contribute to confidence that the tests are working.
There is also a problem with the REQUIRE macro: It does not support concurrent usage from multiple threads. If two threads perform a REQUIRE at the same time, the assertion count is unreliable.
Fix both problems by not using REQUIRE (1) in nondeterministic ways or (2) from multiple threads simultaneously. Instead, we use
check_bool, which will still throw an exception and fail the test, but does not run afoul of REQUIRE's limitations.